In database systems, a stored procedure consists of multiple Structured Query Language (SQL) statements (also referred to herein as queries) to compute a result. The procedures may include sequential execution, branches, loops and invocations to other stored procedures. When the stored procedure is written, developers assume the sequential execution model to get the correct result. However, in some cases, these statements can be scheduled to run in parallel to achieve the best response time. Multiple commercial databases support intra-parallel query, which enables a query to run in multiple smaller pieces in parallel to utilize more resources (e.g., processing cores, memory). This will help in some cases with traditional serial execution schemes. However, some scenarios can benefit from out-of-order (OOO) multiple query execution, where queries or statements are executed out of order or sequence in the procedure. An efficient method to schedule OOO multiple queries within a stored procedure is beneficial, e. g., to achieve improved response time and/or better use resources.